In late 2011, the U.S. Army Corps of Engineers (USACE) approved plans to install a new well and build a new water treatment facility for the city of Roswell in Georgia. Barlovento LLC was selected during a competitive bidding process to provide a treatment system for the new water supply. AdEdge Water Technologies was then contracted to design, manufacture and commission an iron and manganese removal system for the city.
The raw water has an iron concentration of >0.8 mg/L and a manganese concentration of >0.1 mg/L, exceeding the U.S. EPA's standards of 0.3 mg/L and 0.05 mg/L, respectively. The AdEdge treatment system was designed to treat up to 400 gallons per minute (gpm) to serve the water supply wells in removing iron and manganese to EPA standards. The model, APU26-7272CS-2-AVH, was packaged in a compact, skid-mounted unit, utilizing two 72-inch diameter carbon steel vessels in parallel. Each vessel was loaded with AdEdge GS+ media and appropriate support media. The ADGS+ media is a proven manganese dioxide coated media used for the removal of arsenic, iron, manganese and hydrogen sulfide.
The treatment system features also include:
- Pre-chlorination using sodium hypochlorite to oxidize the iron and manganese for optimal removal.
- Sequestering chemical feed pumps that inject ortho-polyphosphates downstream of the APU system to act as a corrosion inhibitor in the distribution piping.
- Post-chlorination for final disinfection in the distribution system.
- System equipment for inline turbidity, pH, and chlorine influent and effluent monitoring equipment.
- Differential pressure monitoring, local pressure gauges, flow sensors and a central hydraulic panel.
- System control provided by PLC and HMI user interface screen. PLC provides control of well pumps and chemical dosing pumps, as well as remote operator plant control.
The AdEdge treatment system was commissioned in late 2012. The system is consistently meeting the effluent treatment goals of 0.3 mg/L for iron and 0.05 mg/L for manganese since it began operation.
Case Study Fast Facts
Client: City of Roswell
Engineer: U.S. Army Corps of Engineers
Design-Build Contractor: Barlovento LLC
Location: Roswell, GA
Date: December 2012
Contaminants treated: Iron, manganese
Flow rate: 400 gpm